In 1284, the village of Hamelin, Germany had a rat problem. So one day, a man in "pied" (multicolored) clothing showed up, and claimed he had a magic flute that he would use to clear the village of rats. The town agreed to pay him a sum of 1000 guilders for the service. And so the Piper reportedly played his magic flute, and led the rats into the Weser river, where all but one drowned.
There are no details known between that event and when the piper returned to the mayor demanding payment. The mayor refused to pay the full amount, instead offering 50 guilders, and even accused the piper of bringing the rats in the first place. The piper vowed revenge.
Then, on St Paul and John's Day, when the town was in church, the piper returned, dressed in green as a hunter would be, and enticed all the children in town to follow him using his magic pipe. He led them into a cave and they were never seen again.
Only 3 children remained: 1 was lame, and couldn't follow fast enough; 1 was deaf, and could not hear the music; 1 was blind, and could not see where he was going. These three children told the town what happened when they came out of church.
Are we supposed to believe the mayor just up and reneged on the agreement for no other reason than he could? That's not what I think, I tell you what.